Metal doors occasionally include an enclosed window pane, often referred to as a “lite” or “light,” in order to permit a user to view conditions on the opposite side of the door. Certain metal doors are intended for use in storm shelters, and are subjected to standardized testing to ensure that the door provides sufficient protection from flying debris that may be carried by high-velocity winds. When a light is installed in such a door, the light often represents a point of failure. For example, the impact may shatter the pane of the light, or may push the pane through the opening in the door skin. For these reasons among others, a need remains for further improvements in this technological field.